Naupactus dissimilis belongs to N. xanthographus species group, revised by Lanteri & del Río (2017). It differentiates from the latter because the elytra are oval, slightly widened relative to pronotum, with a pair of small apical tubercles. The vestiture is brownish-grey with two pairs of whitish stripes along sides and margins of pronotum; the elytra have a distinct white stripe along suture and anterior third of 5º interval, and a small maculae near middle of 3º interval. Scales are rounded, small, and setae are short, recumbent. Corbel of the hind tibiae are broad, squamose, as in N. xanthographus.
Males are absent or scarce in populations of this species. The females are infected with the bacterium Wolbachia, which induces parthenogenesis in several Naupactini (Rodriguero et al. 2010a).
Naupactus dissimilis is associated with horseweed Conyza albida Willd. ex Sprengel (Asteraceae), annual-biennial herb native to South America, and cause minor damage on Citrus maxima Merr. (Rutaceae), Ilex paraguariensis Saint Hill. (Aquifoliaceae) (Lanteri et al. 2002a), and Zea mays L. (Poaceae) (Lanteri & del Río, 2017).
It is mainly associated with vegetation typical of the Paranaense forest and Chaco biogeographic province, near rivers.